[PATCH 5.14 230/849] drm/amd/display: Fix null pointer dereference for encoders

Greg Kroah-Hartman
2021-11-15T22:17:55Z

From: Jimmy Kizito <Jimmy.Kizito@amd.com>

[ Upstream commit 60f39edd897ea134a4ddb789a6795681691c3183 ]

[Why]
Links which are dynamically assigned link encoders have their link
encoder set to NULL.

[How]
Check that a pointer to a link_encoder object is non-NULL before using
it.

Reviewed-by: Aric Cyr <aric.cyr@amd.com>
Reviewed-by: Meenakshikumar Somasundaram <meenakshikumar.somasundaram@amd.com>
Acked-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: Jimmy Kizito <Jimmy.Kizito@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c | 2 +-
drivers/gpu/drm/amd/display/dc/dcn10/dcn10_hw_sequencer.c | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c b/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c
index 3c8da3665a274..7b418f3f9291c 100644
--- a/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c
@@ -4681,7 +4681,7 @@ enum dc_status dp_set_fec_ready(struct dc_link *link, bool ready)
link_enc->funcs->fec_set_ready(link_enc, true);
link->fec_state = dc_link_fec_ready;
} else {
- link_enc->funcs->fec_set_ready(link->link_enc, false);
+ link_enc->funcs->fec_set_ready(link_enc, false);
link->fec_state = dc_link_fec_not_ready;
dm_error("dpcd write failed to set fec_ready");
}
diff --git a/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_hw_sequencer.c b/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_hw_sequencer.c
index 75fa4adcf5f40..da7c906ba5eb5 100644
--- a/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_hw_sequencer.c
+++ b/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_hw_sequencer.c
@@ -1522,7 +1522,7 @@ void dcn10_power_down_on_boot(struct dc *dc)
for (i = 0; i < dc->link_count; i++) {
struct dc_link *link = dc->links[i];

- if (link->link_enc->funcs->is_dig_enabled &&
+ if (link->link_enc && link->link_enc->funcs->is_dig_enabled &&
link->link_enc->funcs->is_dig_enabled(link->link_enc) &&
dc->hwss.power_down) {
dc->hwss.power_down(dc);
--
2.33.0